In order to achieve design goals related to reduction of fuel consumption with its associated advantages of thereby reducing emissions of air pollutants and noise, there is a trend in the commercial aviation industry towards the adoption of turbojet engines having improved design criteria. These new generation turbojet (turbofan) engines are however larger and thus heavier than the existing engine models. On the other hand, newly designed wings are being proposed to match the new generation engines with the ultimate goal of achieving further fuel savings, i.e., wings that sustain lower induced drag due to a larger aspect ratio. These new larger aspect ratio wings however exhibit a characteristic that leads to smaller cross sections with reduced stiffness. Both of these factors contribute to the aeroelastic requirements becoming more critical than for the existing generation of commercial jets.
Taking into account the relatively larger weight and size of the new generation of turbojet engines and the fact that they will be installed under the newly designed wings with larger aspect ratio and thus smaller cross sections, the aeroelastic viability thereby becomes highly dependent on the design of the attachment assemblies to attach the engine mounting pylon to the underside of the wing. The existing solutions for the pylon-to-wing attachment cannot provide an appropriate stiffness for the new mass and geometric characteristics of the newer generation of larger turbojet engines that will readily satisfy flutter certification requirements, particularly when the engine pitch mechanisms are critical to ensure proper engine operation.
Thus, if current pylon-to-wing attachment assemblies are to be adopted for the new generation of turbojet engines, it will become necessary to either increase the structural weight of the wing box or change the wing box construction materials (e.g., from traditional metallic alloys to stiffer and more expensive alternatives such as composite systems).
Therefore, what is needed in this art are turbojet engine pylon-to-wing mounting assemblies that will provide sufficient stiffness requirements to accommodate both the new generation of heavier turbojet engines and the larger aspect ratio (smaller cross-section) aircraft wings. It is towards providing such a solution that the embodiments of the invention disclosed herein are directed.